Hi everyone,

I tried to get through this issue by just looking at the past links/recommendations - here is where I am at and what has been done. Yesterday out of nowhere weird idle (almost stalling) get it into parking lot and crazy idle in P / N - 3000 rpms. Researched, pulled stepper motor, it was really dirty I cleaned it and same result. Replaced stepper motor with new one - slightly better but still around 2300 rpms. I pulled and cleaned the throttle body - no change. Pulled cleaned and inspected VSS , can't say I know if its good or not but no difference noticed. I am stumped right now and don't really want to start crazy chasing/replacing. I also spent time looking for vac leaks and did not identify any. Please any and all help or suggestions! Does the ECU need to be reset? I pulled the batt. for a few minutes etc. hoping maybe it would do it but nothing - PLEASE HELP - thanks ahead of time. Sorry 1997 Disco 1 4.0 - 174 K miles kept and maintained.

 

Clean your t/body, also check for vacuum leaks, especially at the pcv hosrs.

 

I will go through those things again to double check - thanks and I will update, hopefully with better news

 

You may need a new throttle position sensor or you idle reset by the dealer.
You can loosen your TPS and move it to adjust the idle, it wont be accurate but at least it wont be at 3,000rpm.

 

When you clean you TB .. Clean up your throttle linkage and lube it,, Being a fisherman I use a spray called Blakemores Reel Magic. Had this happen on my 97 and as Mike suggested was a loose Vacuum leak at pvc lines I put hose clamps on them .. How Old is your fuel pump and filter ...If thats the original fuel pump Thats alot of miles on it .,Good Luck

 

Replaced the filter 2 months ago and did the whole fuel pump unit about 6 months ago. Ended up adding a inline switch and hotwiring the pump direct since I think the spider harness in dash was the culprit and didn't want to dig in that mess. I haven't had a chance to get back and double check vacuum but will do that as soon as I can - if I end up adjusting the TPS are there any long term issues that will come of it? Thanks for the help.

 

Adjust the TPS as a last resort, no long term effects with that, just that your idle wont be correct, but it will be better than 3k.
The dealer can set the idle correctly for you for around $100.

 

Hey guys - So I went back through everything and found no vac leaks. I did remove the TPS and it resulted in the throttle coming back to "normal" - if I rotated the sensor clockwise while engaged on the unit it reduced the idle - if the sensor was put back to original mount position where the mounting holes lined up it would go back to the high idle. I am fairly sure that it is not a vac leak or anything like that and has something to do with the signal from the TPS? Should I try a new one or is it working fine and its the ECU that needs to just be rest? I want to make sure before I adjust the mounting holes to give me the idle range I need. I am at the last resort Spike like you said and just want to make sure its ok until i can get it set by a dealer. On that note is there no way at all to do so without going to a dealer??? Thanks for the help

 

Go ahead and move the TPS to reduce your idle to a resonable speed and then have the dealer reset it to spec when you can.
If they say you need a new TPS then fine, but until then...

 

I have same problem with high idle. We took plenum off and cleaned it. Before doing that, the car would not stay running: too low idle. After cleaning and replacing plenum: 2300 RPM. I have 97 Discovery. Can Indy's do idle adjust? Or only dealer for $100? Hayne's Rover book suggested that there is an adjusting screw beneath tamper proof cap.
Thank you